Weigh beam



April 3, 1928.

A. BOUSFIELD WEIGH BEAM Filed Jan. 22. 1926 2 Sheets-Sheet 1 Med 190' INVENTQR I usfield,

ATTORNEY Patented Apr. 3, 1928.

UNITED STATES PATENT OFFICE.

ALFRED IBOUSFIELD, OF ST. JOHNSBURY, VERMONT, ASSIGNOR TO E. AND T. FAIR- BANKS AND COMPANY, OF ST. JOHNSBURY, VERMONT, A CORPORATION OF VER- MONT.

WEIGH BEAM.

Application filed January 22, 1926. Serial No. 82,918.

This invention has reference to weighbeams and aims to provide a device of this character presenting certain improvements over articles of a similar nature as heretofore constructed.

The invention has for a general object improvements in the construction of a weighbeam whereby the means used to connect the load transmitting rod of a weighing scale to the weigh-beam can be so positioned that the load stresses will be transmitted to the longitudinal center line of the beam.

Another object is to provide a weigh-beam with a recess formed therein, the recess being so constructed as to comprise a rectangular opening disposed transversely of the beam and a vertical slot extending downwardly from the rectangular opening to the bottom of the beam.

A still further object is to provide an improved weigh-beam which is relatively simple, reliable and exact in function under varying conditions of service.

Other objects will be in part obvious from the following detailed description and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the application of which will be indicated in the following claims.

For a complete understanding of the 11a" ture of the invention reference should be had to the accompanying drawings wherein- Figure 1 is a side elevation of a weighbeam and associated parts crmstructed according to my invention;

Fig. 2 is a vertical section taken on the line 22 of Fig. 1;

Fig. 3 is a vertical section taken on the line 33 of Fig. 2;

Fig. 4 is a similar view taken approximately on the line 44 of Fig. 2;

Fig. 5 is a detail view of one of the pivots, and

Fig. 6 is a similar View of one of the bearings.

Referring now to the drawings, the weighbeam comprises a relatively long, rectangu larly shaped bar 1, having a thickened portion 2 near'one end for reinforcing purposes. A track 3, carrying a poise 4, extends forwardly from the port-ion 2, and the bar 1 terminates in a tip 5. Projecting from the portion 2 opposite to the track portion is a rear end or butt 6. The poise 4, which can be of any approved design, has a pointer 7 for indicating weights marked on the scale graduations 8 with which the face of the bar is provided.

In order that the load stresses from the lever system of the scale (not shown) may be transmitted to the beam, the portion 2 is provided with a pair of spaced rectangularly shaped openings 9 and 10. The opening 9 has a notch 11 cut into its upper edge for the reception of a knife edge pivot 12, while the opening 10 has a notch 13 cut into its lower edge for the reception of a knife edge pivot 14. The pivot 12 is disposed transversely of the beam and the ends of the pivot project from each side thereof. This pivot is adapted to be detachably secured to the beam by means of a screw 15.

For the purpose of supporting the beam,

use is made of a stand 16, mounted on a suitwalls of the slot are inclined away from each other. as shown by Fig. 3. By this construction the mouth of the slot is considerably wider than the width of the opening 10. On the other hand, by referring to Fig. 2, it will be seen that the opening 10 and the slot 19, together, form a T-shaped recess in the beam, which recess is spanned the pivot 14.

As is customary in the construction of weigh-beams, the tip 5 is provided with a knife edge pivot 20. The end of the beam is formed with a rectangular opening 21, having a notch 22 formed in its lower edge, and the pivot 20 is mounted in the notch. Suspended from the pivot 20 is a loop 23, carrying the upper hooked end of a counterpoise supporting rod 24. A trig stand 25 is supported on the beam'shelf 17 and arranged to co-operate with the tip to indicate balanced position of the beam and to limit to prevent the hearing from sliding alongvertical swing thereof, or to lock the same in immovable position by means of a pivoted trig 26.

In order that. the pivot It may be quickly attached or removed from its seat in the notch 18, one side of the pivot is tapered, or inclined, as indicated by the numeral 27. A block 28, having a face inclined. to correspond with the inclined face of the pivot, is inserted in the notch, being retained in position by a screw 29 passed upwardly through an opening 80 in the side of the beam. In the present instance, two blocks aroused, one on each side of the slot 19. The blocks function as wedges, and hence will clamp the pivot in position and prevent any rocking tl ereof, when the screws 2.9 are turned up tight. By referring to 2 and 5, it will be observed that the pivot I i has a length approximately coinciding with the width of the portion 9. of the beam. However, on account of the great stresses to which this pivot is subjected during use, it is made unusually high in comparison to its length, so that it has a very stocky appearance.

Suspended from the pivot 14:, is a loop 31, in the form of a plate having a rectangular opening 32 positioned, near its top, and an annular opening 33 positioned near its bottom.

is hearing block 34, having a concaved groove 35, for engaging with the edge of the loop, is inserted in the opening 32. The block, which is substantially rectangular in form, is arranged transversely to the loop, so as to overlie the pivot 14. The groove is cut transversely of the bearing so as to lie along the longitudinal center line of the beam.

The portion of the opening in which the grooved portion 35 of the bearing is mounted is rounded, the, radius of curvature being less than the radius of cuiazature of the concaved groove. In this waygihere will only be a line contact between the bearing and the loop, and friction at this point will be reduced to a minimum.

The sides of the opening 32' which are disposedadjacent to the bearing 34, are restricted somewhat in comparison to the width of the other part of the opening. This, it will be noticed, provides a space having a width only slightlyv greater; than the width of the bearing, and in this man ner, excessive lateralmovement of the bearing with respect to the loop will be prevented; concaved, as indicated at 36, providing a defined seat for the knife edge of the pivot 1 1.

The bearing 34 has a length that is less than the length of the pivot 14:, and inorder the knife edge of the pivot, the knife edge, instead of being formed along th upper The lower edge of the bearing is also memos face of the pivot, as has'general-ly been the custom in devices of this character, is recessed in the pivot body, as indicated by the numeral 87 (Figs. 2 and 5). This recessing of the knife edge enables shoulders 38 to be formed along the top of the pivot adjacent each end thereof, such shoulders serving as stops against which the ends of the bearing can abut, should the parts shift with respect to each other.

The knife edge 37 of the pivot let can be formed with sides having. any desired inclination. ders 38 are also inclined. This construction of the shoulders is not necessary, and if so desired the top of the shoulders can be flat, or have any, other desired configuration. lilowever, in manufacturing the-pivot it is desirable to provide a gauge for the knife: edge. Hence, if the top of the shoulders 38 are formed with inclined'surfaces that corredisposed directly beneath the beam, and haw ing spaced legs 41. The legs are provided with alined apertures 42. A pin 43 is passed through the apertures 42 of the yoke and the opening 33 of the loop. The pin has a concaved groove 44s formed therein for engaging with the edge of the opemng 33. The lowerv portion of the opening 33 is rounded, the

radius of'curvature being less than the radius of curvature of 'the concaved groove in the pin. In this way, there will only be a line contact between the pin and the loop. and friction at this point will be reduced to -a minimum. The line of contact is disposed along the longitudinal center line of the beam. This construction, itewill be noticed, also prevents the pin from sliding with respect to the loop. However, cotter pins 45 are mounted in the extremities of the pin to serve as auxiliary means for retaining the parts together. The cotter pins are spaced from the sides of the yoke, so as to maintain a loose connection therebetween, which is desirable.

During the operation of the device, there is a tendency for a vibratory movement being imparted to the rod 39. Therefore, the loop should be free to swing on its pivotal connection longitudinally with respect tothe' beam. Hence, the desirability of' forming the slot 19 in the manner shownfwill bereadily apparent.

The construction described provides'in ef feet a universal joint between the load transmitting rod and the weigh be'ami At As shown, the top of the shoul-' the same time, the disposition of the pivotal bearing points is such that the load is transmitted substantially linearly at the intersection of the center planes of the loop and the beam. l urtherniore, the above described connection between the load transmitting rod and the Weigh-beam permits ready adjustment of the parts, and easy replacement, when desired. As the loop projects into the beam and is pivoted thereto along its longitudinal center line, load stresses will be transmitted centrally of the beam without causing rocking thereof.

Means for completing the precise balancing of the beam in zero or no loid position are provided by a balance ball 46.

For the purpose of enabling the ball to be moved longitudinally, a rod 47, threaded through the ball, is rotatably mounted in the upper ends of a pair of standards 48, spaced from each end of the ball. The ball is restrained from rotation by a rod 49 connect-- ing the standards and bearing against the lower edge of the ball. The red I? is provided at its outer end with an operating hand wheel 50.

In order that the ball may be vertically shifted with respect to the end of the beam, the standards l8 are formed with threaded shanks 51 which are passed downwardly through openings 52 formed in the butt (5. Nuts 53 are mounted on the shanks to bear against the upper edge of the beam, while nuts 54 are mounted on the lower ends of the shanks to bear against the bottom of the beam.

By this construction, the balance ball can be shifted longitudinally and vertically to adjust the center of gravity of the beam rela tively to its supports. The preliminary adjustn'ien't is accomplished by raising or lowering the standards -l8 carrying the ball, by turning the nuts 53 and 54 up or down, and the final adji'istment being obtained by inanipulating the hand wheel 50, to move the hall longitudinally of its support.

It will furthern'iore be perceived that the construction of the connecting means between the load transmitting rod and the weigh-beam utilized in my present invention is of such a nature as to constitute a considerable improvement over mechanisms as heretofore provided, in that aside from other advantages achieved, the liability of damage occurring to the parts is reduced to a 1ninimum. Also, it will-be noted that by means of a loop provided within the scope of the present invention, such for instance that il lustrated, the simplicity of the construction is materially enhanced, especially when such loop is used with a weigh-beam constructed according to that shown and described herein.

Thus among others, the objects aforementioned are accomplished and it will be perceived that the mechanism may be rearranged and modified according to the most desirable practice, and that any suitable bearings and pivots may be used in lieu of those herewith shown.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and spe cific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim is 1. In combination, a weigh-beam having a T-shaped recess formed therein, comprising a rectangular opening extending laterally of said weigh-beam and a vertical slot arranged centrally of said weigh-beam and extending downwardly from said rectangular opening, a pivot in said rectangular opening and means for positively clamping said pivot in position.

2. In con'ibination, a weigh-beam having a T-shaped recess formed therein, comprising a rectangular opening extending laterally of said weigh-beam and a vertical slot arranged centrally of said weigh-beam and extending downwardly from, said opening, said slot having its end walls inclined outwardly to form an enlarged mouth on the under face of the beam, a pivot in said rectangular opening and wedge means for positively re taining said pivot in position.

In testimony whereof I hereunto sign my name.

ALFRED BOUSFIELD. 

